Hydrodynamic machine for testing strength of materials



C. LOWTHORP.

Testing Apparatus.

Patented May 26, 1857.

No. 17,383. V

N PE IRS. Photo-HWY, Wm mDC.

UNITED STATES PATENT ormcn.

FRANCIS C. LOW'TI-IORP, OF 'IIKIGN'ION, NEIV JERSEY.

HYDRODYNAMIG MACHINE FOR TESTING STRENGTH OF MATERIALS.

Specification of Letters Patent No. 17,383; dated May 26, 1857.

To all whom it may concern:

Be it known that I, F RANCIS O. Low'rnonr, of the city of Trenton, inthe county of Mercer and State of New Jersey, have invented certain newand useful Improvements in Machinery for Testing the Strength ofMaterials; and I do hereby declare the following to be a full, clear,and exact description of the same, reference being had to theaccompanying drawing and to the letters of reference marked thereon.

My invention relates to machinery for as certaining the amount oftensile or transverse strain, or torsion, or crushing force whichmaterials are capable of withstand.

ing, and consists in so combining suitable gearing and other mechanism,for applying said strains or forces, with a piston or plunger operatingagainst a body of water or other suitable fluid, within a cylinder orbarrel, that on applying the force or strain to the object to be tested,the gearing, such a pressure shall be transmitted to the fluid in thecylinder or barrel, and to any suit-able indicating apparatus inconnection with the same, as to enable the attendant to readilycalculate the amount of strain or force to which the object has beensubmitted.

My invention has for its aim the testing of a succession of objects withgreater ease and rapidity than the same can be accomplished by hydraulicrams, complex levers, and other cumbrous and tedious appliances hithertoused for the same purpose.

In order to enable others skilled in the art to make and use myinvent-ionI will now proceed to describe its construction and apparatus;Fig. 2, a ground plan of the same; Fig. 3, an end view looking in thedirection of the arrow 6 (Fig. 2,); Fig. 4, a section on the line 1, 2,(Fig. 2,) and Fig. 5, an end view looking in the direction of the arrow7 (Fig. 2).

Similar letters refer to similar parts throughout the several views.

Two substantial beams, one composed of the longitudinal pieces A. B, andC and the other of the pieces A, B, and O are placed a suitable distanceapart and connected together by the cross pieces D, I) and I) and stayedby the diagonal braces Z), 5, Z), 5. The

intermediate pieces B and B are narrower than the upper and lower piecesin order that a groove may be formed on the inside of the two mainbeams. Across the opposite end of these beams are secured the upper beamE and lower beam F and to the former are secured two longitudinal beamsG and G to the end of which is attached another cross piece H of thesame size and form as E, the inner ends of the pieces G and dr beingsecured to the cross piece I, which, together with a similar piece J issecured to the main beams. On the cross pieces I and "I is erected alight framework composed of the uprights e and e and cross piece f.

The above forms the framework of the apparatus which may be extended toany length desired. 7

Near one end of the frame and between the two main beams is firmlysecured a cylinder K the center line of which coincides with the centerof the grooves on the inside of the beams. This cylinder is bored outperfectly true and is furnished with covers 9 and y, piston, stuifingbox It, and piston rod L, all constructed and arranged similar to thoseof an ordinary steam engine.

On the top of the cylinder are two orifices i, and 2" one communicatingwith the interior of the cylinder on one side of the piston and theother with the interior of the cylinder on the opposite side of the piston so that the pipe j which communicates with the pressure gage M, onthe cross piece f, may be attached to one or other opening, theindicator being so arranged on the cross piece as to be readily removedfrom a position above one opening to that above another. On the top ofthe cylinder and communicating with the interior of the same, onopposite sides of its piston, are two openings Zr and 76 for theadmission of air and water as hereafter set forth.

To the piston rod L is firmly secured a cross head N having hubs at eachend which slide in grooves on the inside of the opposite main beams, asseen at Fig. 4. In the hubs of this cross head fit the shafts O and Osupplied on each side of the hubs with collars so that they may turnfreely but have no longitudinal movement independent of the crossheadand piston rod. Toward the ends of the shafts O and O are cutscrewsadapted to similar screws cut in the hubs at the end of the cross headP, which is also face to represent pounds.

arranged to slide in the grooves on the inside of the main beams. A spurwheel Q. with a pinion R attached turns loosely on the piston rod L, thepinions S and S gearing into the wheel Q and the wheels T and T into thepinion R. The wheels T, and T are secured respectively to the screwshafts O and O and into these wheels gear the pinions m and m on theshafts n and n which turn in boxes 7) and 22 secured to the underside ofthe beams E and H. The ends of the shafts a and a are n and n aresquared for the purpose of receiving Stiltable handles by which they maybe turned. The pinions S and S and m and m may be either sufficientlybroad to remain always in gear with the wheels during the lateralmovement of the latter in connection with the piston rod, and screwshafts; or may otherwise be arranged to slide on their shafts. Anothercrosshead V is arranged to slide with its opposite ends in the groovesof the main beam and is securely confined to the desired position bymeans of the keys WV, V, which fit into slots cut perpendicularly intothe main beams which are perforated with similar slots at differentintervals throughout the length in order that the position of thecrosshead may be changed to suit the object to be tested.

The two cross heads V and P have oblong holes passing entirely throughthem and at right angles to these are round holes for the reception ofthe pins 9 q as seen in Fig. 5.

Supposing it be required to test the tensile strain of the rod X as wellas the strength of the eyes at each end of the same. The crosshead Vhaving been secured to its proper position by means of the keys V andthe eyes of the rod X inserted into the oblong holes in the cross headsand secured thereto by pins the cylinder K being supplied with waterbetween the piston and cover 9, and that water being in communicationthrough the pipe 7' with the pressure gage M, the orifice is beingclosed and either or both of the orifices a" and open, and the pinions Sand S in gear with the wheel Q the machine is ready to be put inoperation.

Supposing the rod X to have a sectional area of one inch and it berequired to test it to a tensile strain of ten tons to the inch, andsupposing the cylinder to be 20 inches in diameter or anarea of 314inches and the pressure gage to be marked on the The attendant orattendants turn either one or both of the shafts V or V in the directionof their arrows, this through the wheel Q, pinion R and wheels T and Tcauses the screw shafts O and O to turn in the direction of theirarrows, and these screws having right handed threads it is evident thatthe crosshead P must be drawn toward the crosshead N submitting the rodX to a tensile strain which increases as the wheels continue to beturned.

Should the pointer on the face of the pressure gage reach 100 lbs. it isevident the strain on the rod will be one hundred times the area of thecylinder, which we have already supposed to be 314 inches, so that thestrain would be thirty one thousand four hundred and sixteen pounds, orabout ten tons.

hen it is desirable to ascertain the amount of compression whichmaterials will withstand, the crosshead V is secured in proximity to thecrosshead P the pipe j of the indicator connected to the orifice i, theorifice is closed and the orifices 2' and is remaining open, the wheelsare turned in a contrary direction to that pointed out by their arrowscausing the crosshead P to ap proachthe crosshead V compressing theintervening material until the amount of com pression is designated bythe pointer of the pressure gage as before.

The facility with which materials can be submitted to a transversestrain by the above apparatus will be readily understood without furtherexplanation.

The rod having been tested the wheels are turned in a direction contraryto that pointed out by the arrows which causes the crosshead P toapproach the crosshead V when the pins g, g, are removed and the testedrod replaced by another. In order to facilitate the movement of thescrew shafts during certain portions of their operation the handles arechanged from the shafts U and U to the shafts n and 'n and as thepinions m and m gear directly into the wheels T and T it is evident thatthe movements must be more rapid than before. lVhen it is desirable toascertain what amount of torsion or twisting strain a shaft 3 is capableof bearing, I secure it to blocks 2 which are firmly attached to theopposite main beams, and partially surrounding the wheel 4 which is alsosecured to the shaft with a chain to the end of which is connected thecrosshead P, the wheels are turned as before'until the pressure of thewater in the cylinder moves the pointer of the pressure gage to therequired mark, the leverage afforded by the wheel 4 being taken intoconsideration.

It will now be seen that objects may be acted upon by my improvedapparatus in much more rapid succession than by com pleX arrangements ofscrews and levers, hydraulic rams, and other contrivances for effectingthe same object.

I do not desire to confine myself to the precise form of the frameworkor to the material of which it is constructed to the precise arrangementof gearing shown, or to any particular construction of indicator,inasmuch as the frame may be of any length,

Width, or shape to suit the objects to be tested, may be made of ironinstead of Wood, as the system of gearing may be modified Withoutaltering the result, and as a Weighted Valve or other indicator may beused instead of a pressure gage, but

What I claim and desire to secure by Let ters Patent is,

The combining of gearing and other suitable mechanism for applyingstrains or forces to the object to be tested, With a piston or plungeroperating against a body of Water Within a cylinder or barrel in such ascribing witnesses.

F. C. LOWTHORP. Vitnesses JOSHUA STABLER, JESSE SAMUELs.

